Ionic Crystal Lattice

• An ionic crystal lattice is an array of oppositely charged ions held in fixed positions by strong electrostatic forces
• Hard and brittle due to strong electrostatic forces between oppositely charged ions
• High melting and boiling points as lots of energy is needed to break the strong electrostatic forces
• Can conduct electricity when molten or in solution, as ions are free to move
• Cannot conduct electricity when solid as ions are held in fixed positions
• Caesium ions are much larger than sodium ions so more chloride ions can fit around it